Method for preparing perovskite thin film through evaporation and application of perovskite thin film in perovskite photovoltaic device

Abstract

The invention discloses a method for preparing a perovskite thin film through evaporation and application of the perovskite thin film in a perovskite photovoltaic device, the method comprises the following steps: S1, a substrate is placed in an evaporation cavity, co-evaporation of inorganic salt and an inducer is carried out, the inorganic salt comprises lead iodide, and the inducer is selected from one or more of cuprous iodide, methyl iodide and hydroiodic acid; s2, organic salt is evaporated, annealing treatment is carried out, and the perovskite thin film is formed on the surface of the substrate; the organic salt comprises FAI. According to the invention, the strong coupling effect of lead iodide and FAI is increased by introducing the inducer in the sequential evaporation process, the reaction of lead iodide and FAI is promoted, and the perovskite thin film with low defect and high crystal quality is obtained. The invention further provides a method for preparing the perovskite photovoltaic device through full evaporation, industrial production of perovskite solar cells can be achieved, and the prepared perovskite photovoltaic device has high conversion efficiency and good stability.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic device preparation, and in particular to a method for preparing a perovskite film by evaporation and an application thereof in a perovskite photovoltaic device. Background Art

[0002] Perovskite solar cells (PSCs) are solar cells that use perovskite structural materials as light-absorbing materials. They belong to the third generation of thin-film cells and have the characteristics of high energy conversion efficiency, low price, light weight, and high flexibility. Compared with the current mainstream silicon-based solar cells, they have shown great potential. However, the preparation of perovskite solar cells currently lacks a process that can achieve commercial production, which limits its practical application. Most photovoltaic devices moving towards commercialization rely on vacuum deposition technology in front-end deposition technology. For example, organic light-emitting diodes (OLEDs), cadmium telluride (CdTe), copper indium gallium selenide (CIGS), etc. have successfully used vacuum deposition technology to achieve the commercialization of traditional photovoltaic devices. In contrast, PSCs with similar processes and structures mainly rely on wet processing methods, and there have been no reports of commercial production using these methods. This difference not only deviates from traditional practices, but also poses a significant risk to the commercialization of PSCs. Therefore, it is necessary to explore the vacuum deposition technology of perovskite films and devices, and at the same time study their crystallization dynamics and carrier transport processes.

[0003] The sequential evaporation process used to prepare perovskite films separates the deposition of inorganic and organic salts, simplifies the film manufacturing process, and overcomes the challenge of organic salt evaporation rate in the one-step co-evaporation process. However, the sequential evaporation process usually requires subsequent annealing to promote the complete reaction between inorganic and organic salts to form the perovskite phase. Although the solvent has been removed, these films still suffer from incomplete reaction, many defects, and poor crystal quality, which seriously limits the further improvement of device performance. Summary of the invention

[0004] The present invention provides a method for preparing a perovskite film by evaporation and its application in a perovskite photovoltaic device. An inducer is introduced into the process of sequentially evaporating the perovskite film, and the strong coupling effect between the inducer and PbI2 / FAI is utilized to induce the reaction between the two, thereby effectively suppressing the defects of the film and improving the crystallization quality of the film. In addition, the present invention can realize the full evaporation preparation of the perovskite photovoltaic device by selecting the hole transport layer material and optimizing the evaporation method of the perovskite film, and the prepared perovskite photovoltaic device has high conversion efficiency and good stability.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A first aspect of the present invention provides a method for preparing a perovskite film by evaporation, comprising the following steps:

[0007] S1. Placing the substrate in a vapor deposition chamber, and co-evaporating an inorganic salt and an inducer, wherein the inorganic salt comprises PbI2, and the inducer is selected from one or more of cuprous iodide (CuI), methyl iodide (CH3I), and hydroiodic acid (HI);

[0008] S2, vapor-depositing an organic salt and performing annealing to form the perovskite film on the surface of the substrate; the organic salt comprises formamidine hydroiodide (FAI).

[0009] The preparation of perovskite films based on co-evaporation of inorganic salts and organic salts has problems such as low preparation efficiency, poor film uniformity (large difference in the evaporation rate of the two salts), and impurities (organic salts will decompose during the long-term evaporation of inorganic salts). Currently, the deposition of inorganic salts and organic salts is separated by sequential evaporation process in order to overcome the above problems. However, in actual operation, the organic / inorganic components in the sequential evaporation perovskite film are not completely reacted, resulting in the Pb 0 The increase of vacancy defects limits the improvement of device performance. Based on the above problems existing in the sequential evaporation preparation of perovskite films, the inventors adjusted the evaporation method through continuous attempts and accidentally discovered that by co-evaporating a specific inducer with an inorganic salt and then evaporating an organic salt, the defects of the perovskite film can be effectively suppressed and the crystallization quality of the film can be improved. Further verification found that this is because the inducer has a strong coupling effect with PbI2 and FAI. Under the action of the inducer, the two can be fully reacted, thereby reducing the defects of the perovskite film.

[0010] Furthermore, in S1, the evaporation rate of PbI2 is preferably For example Etc., including but not limited to the evaporation rates listed above.

[0011] Furthermore, in S1, the evaporation rate of the inducing agent is preferably For example wait.

[0012] Furthermore, in S1, the inorganic salt also includes one or more of PbCl2, CsI, CsBr, and PbBr2.

[0013] Furthermore, in S2, the evaporation rate of FAI is preferably For example

[0014] Furthermore, in S2, the organic salt may also include methylamine hydrochloride (MACl).

[0015] Furthermore, in S2, the temperature of the annealing treatment is preferably 140-170° C., such as 150° C., and the annealing time is 10-20 min.

[0016] The second aspect of the present invention provides a perovskite film prepared by the preparation method described in the first aspect.

[0017] Furthermore, the perovskite film may be FACs x Pb 1-x I y Br 3-y , where 0≤x≤1, 0≤y≤3; for example, FACs 0.05 Pb 0.95 I3 perovskite thin film.

[0018] The third aspect of the present invention provides a perovskite photovoltaic cell, comprising the perovskite film described in the second aspect.

[0019] Furthermore, it comprises a transparent conductive substrate layer, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and an electrode layer which are stacked in sequence; wherein,

[0020] The material of the hole transport layer is selected from one or more of [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid (Me-2PACz), [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid (Me-4PACz), and polymer SAM (Poly-SAM);

[0021] The perovskite layer is the perovskite film;

[0022] The material of the electron transport layer is fullerene (C60) and / or tin oxide (SnO2);

[0023] The material of the hole blocking layer is 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP) and / or 2,2',2"-(1,3,5-triphenylbenzene)-tris[1-phenyl-1H-benzimidazole] (TPBi);

[0024] The material of the electrode is selected from one or more of silver (Ag), gold (Au), and copper (Cu);

[0025] In some preferred embodiments of the present invention, Me-2PACz is used as a hole transport layer material, C60 is used as an electron transport layer material, BCP is used as a hole blocking layer material, and Ag is used as an electrode material to prepare the above-mentioned perovskite photovoltaic device.

[0026] Furthermore, the thickness of the hole transport layer is preferably 2-50 nm, for example, 2 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, etc., including but not limited to the thickness values ​​listed above.

[0027] Furthermore, the thickness of the perovskite layer is preferably 500-800 nm, for example, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm, etc., including but not limited to the thickness values ​​listed above.

[0028] Furthermore, the thickness of the electron transport layer is preferably 5-20 nm, such as 5 nm, 10 nm, 15 nm, 20 nm, etc., including but not limited to the thickness values ​​listed above.

[0029] Furthermore, the thickness of the hole blocking layer is preferably 5-15 nm, such as 5 nm, 10 nm, 15 nm, etc., including but not limited to the thickness values ​​listed above.

[0030] Furthermore, the thickness of the electrode layer is preferably 50-200 nm, such as 50 nm, 100 nm, 150 nm, 200 nm, etc., including but not limited to the thickness values ​​listed above.

[0031] The fourth aspect of the present invention provides a method for preparing the perovskite photovoltaic cell according to the third aspect, comprising the following steps:

[0032] (1) placing a transparent conductive substrate in a vapor deposition chamber, and vapor depositing a hole transport layer material to form a hole transport layer; the hole transport layer material is selected from one or more of Me-2PACz, Me-4PACz, and Poly-SAM;

[0033] (2) co-evaporating an inorganic precursor source and an inducer on the hole transport layer, and then evaporating an organic precursor source, and performing annealing to form the perovskite layer on the substrate surface; the inorganic precursor source comprises PbI2, the inducer is selected from one or more of CuI, CH3I, and HI, and the organic precursor source comprises FAI;

[0034] (3) Sequentially evaporating an electron transport layer material, a hole blocking layer material and an electrode material on the perovskite layer to prepare the perovskite photovoltaic cell.

[0035] At present, perovskite photovoltaic cells are mostly prepared by wet processing methods or wet processing combined with evaporation, which is not conducive to the industrial production of perovskite photovoltaic cells. To solve the above problems, the present invention provides a method for preparing perovskite photovoltaic cells by full evaporation, wherein specific hole transport layer materials such as Me-2PACz, Me-4PACz, and Poly-SAM are used. Compared with other commonly used hole transport materials, this type of specific hole transport layer material can be used to prepare a uniform hole transport layer by evaporation. By selecting specific hole transport layer materials and optimizing the evaporation method of the above perovskite film, full evaporation preparation of perovskite photovoltaic devices can be achieved, and the prepared perovskite photovoltaic cell has high conversion efficiency and good stability.

[0036] Furthermore, the evaporation rate of the hole transport layer material is preferably

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The present invention provides a method for preparing perovskite thin films by evaporation, wherein an inducer is introduced into the process of sequential evaporation to prepare perovskite thin films, and the strong coupling effect between the inducer and PbI2 / FAI is utilized to induce the two to fully react, thereby effectively suppressing film defects, improving film crystallization quality, and enhancing device performance.

[0039] 2. The present invention provides a method for preparing perovskite photovoltaic cells by full evaporation. By selecting hole transport layer materials and optimizing the evaporation method of the above-mentioned perovskite film, full evaporation preparation of perovskite photovoltaic devices can be achieved. The above-mentioned preparation process does not involve the use of solvents and has good controllability. The thickness and uniformity of the film can be accurately controlled, and it is suitable for industrial production.

[0040] 3. The perovskite photovoltaic cell prepared by the above method has high photoelectric conversion efficiency and good stability. 2 ) device achieved a conversion efficiency of 20.30% with an active area of ​​6.07 cm 2 and 15.5cm 2 The devices achieved conversion efficiencies of 19.58% and 19.26%, respectively. Meanwhile, the cells treated with the inducer CuI maintained more than 80% of their initial efficiency after more than 3200 hours of maximum power point tracking (MPPT) testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 Schematic diagram of the device structure and process of the fully evaporated perovskite photovoltaic device (below);

[0042] Figure 2The perovskite film before and after the introduction of CuI (a is before the introduction, b is after the introduction) cross-sectional scanning electron microscopy (SEM), (c is before the introduction, d is after the introduction) cross-sectional electron energy dispersive spectroscopy (EDS), (e is before the introduction, f is after the introduction) wide-angle X-ray scattering (GIWAXS) images;

[0043] Figure 3 DFT calculation of the electron localization function diagram of CuI and PbI2 (left) and CuI and FAI (right);

[0044] Figure 4 X-ray photoelectron spectroscopy (XPS) diagram of Pb and N before and after CuI treatment;

[0045] Figure 5 The current-voltage curves of fully evaporated perovskite photovoltaic devices with different effective areas;

[0046] Figure 6 Long-term stability of the device at the maximum power point (MMPT) before and after the introduction of CuI. DETAILED DESCRIPTION

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items. The term "includes" or "comprising" described in the present invention means that it may include or contain other components in addition to the components described. The term "includes" or "comprising" described in the present invention may also be replaced by the closed form "for" or "consisting of..."

[0048] The present invention is further described below in conjunction with specific embodiments and drawings so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0049] Example 1

[0050] This embodiment relates to the preparation of a perovskite photovoltaic cell, which is specifically as follows:

[0051] (1) The ITO substrate was cleaned in an ultrasonic bath with deionized water, acetone, and ethanol for 15 minutes each;

[0052] (2) The substrate treated in step (1) is moved to the evaporation chamber, and Me-2PACz is evaporated at a rate of A hole transport layer with a thickness of 15 nm was prepared;

[0053] (3) Continue to evaporate the perovskite layer on the hole transport layer. First, co-evaporate PbI2, PbCl2, CsI and CuI to a total thickness of about 300nm, where the PbI2 evaporation rate is The PbCl2 evaporation rate is The CsI evaporation rate is The evaporation rate of CuI is Then, FAI with a thickness of about 350 nm was evaporated at a rate of Performing annealing treatment at a temperature of 150° C. for 10-20 minutes to prepare a perovskite layer;

[0054] (4) evaporating C60 with a thickness of 5-20 nm on the perovskite layer to form an electron transport layer;

[0055] (5) evaporating a BCP with a thickness of 5-15 nm on the electron transport layer to form a hole blocking layer;

[0056] (6) About 100 nm of silver is evaporated on the hole blocking layer to prepare a perovskite photovoltaic device.

[0057] Example 2

[0058] This embodiment relates to the preparation of a perovskite photovoltaic cell, and the only difference from Embodiment 1 is that the inducer used is HI, and the inducer HI is involved in the evaporation process in a gaseous state, and the other operations are the same, and the corresponding perovskite photovoltaic device is prepared.

[0059] Example 3

[0060] This embodiment relates to the preparation of a perovskite photovoltaic cell, and the only difference from Embodiment 1 is that the inducer used is CH3I, and the inducer CH3I is introduced into the evaporation process in a gaseous state, and the other operations are the same, and the corresponding perovskite photovoltaic device is prepared.

[0061] Example 4

[0062] This embodiment relates to the preparation of a perovskite photovoltaic cell, and the only difference from Embodiment 1 is that the SAM material used is Poly-SAM, and the other operations are the same, and the corresponding perovskite photovoltaic device is prepared.

[0063] Comparative Example 1

[0064] This comparative example involves the preparation of a perovskite photovoltaic cell, which is different from Example 1 only in that CuI is not introduced during the preparation of the perovskite layer, and the other operations are the same to prepare the corresponding perovskite photovoltaic device.

[0065] Comparative Example 2

[0066] This comparative example involves the preparation of a perovskite photovoltaic cell, and the only difference from Example 1 is that a hole transport layer is prepared by spin coating.

[0067] Characterization and Application

[0068] (1) Study the effect of inducers on perovskite films

[0069] The perovskite layers prepared in Example 1 and Comparative Example 1 were characterized by the following SEM, EDS and GIWAXS. The cross-section of the perovskite layer prepared without the introduction of CuI (Comparative Example 1) and with the introduction of CuI (Example 1) is shown in FIG. Figure 2 As shown in a and 2b, it can be seen from the figure that the CuI-based perovskite film shows less PbI2 and shows a continuous large grain size, indicating the improvement of the quality of the perovskite film. Figure 2 c (Comparative Example 1) and 2d (Example 1) are EDS images of the cross section of the perovskite layer. It can be seen from the figure that the introduction of CuI can effectively reduce the stratified distribution of C and Pb, thereby highlighting the significant ability of CuI to promote the combination of PbI2 and FAI. The wide-angle X-ray scattering images of the above cross sections are shown as follows: Figure 2 As shown in Figures 2e (Comparative Example 1) and 2f (Example 1), the untreated perovskite film shows a stronger PbI2 peak. After the introduction of CuI, the disappearance of the lead iodide peak further illustrates the thorough reaction of PbI2 and FAI.

[0070] It can be seen that the introduction of the inducer CuI can effectively reduce film defects, improve the crystallization of perovskite, and thus obtain high-quality perovskite films.

[0071] In order to further explore the mechanism of action of the inducer in the formation process of perovskite film, the present invention uses DFT to calculate the interaction between CuI, PbI2 and FAI. The corresponding electronic localization diagram is shown in Figure 3 As shown in the figure, it can be seen that CuI can interact with PbI2 and FAI through ionic bonds at the same time, thereby achieving the effect of inducing reaction. Figure 4 From the XPS spectrum, it can be found that the Pb 4f and N1s peaks have shifted significantly, indicating that CuI can interact with the Pb in PbI2 and the N element in FAI.

[0072] (2) Study the photoelectric performance of different perovskite photovoltaic devices

[0073] 1. Preparation of fully evaporated perovskite photovoltaic devices with different effective areas: The preparation process is consistent with Example 1. By controlling the area of ​​the evaporation mask and the substrate, different active areas of 0.1 cm 2 、6.07cm 2 and 15.5cm 2Perovskite photovoltaic devices.

[0074] The active areas of the prepared samples were 0.1 cm 2 Perovskite photovoltaic devices.

[0075] 2. Photoelectric performance test: The J–V characteristics of each device were tested using a Keithley 2400 source meter to simulate the AM 1.5G spectrum at 100mWcm-2. 2 For the perovskite solar cell module, the test voltage range is fixed at 0 to 8V.

[0076] Figure 5 The current density-voltage characteristic curve of perovskite photovoltaic devices with different active areas. The conversion efficiency of perovskite photovoltaic devices with different active areas is as follows: The active area is 0.1cm 2 The conversion efficiency is 20.30%, 6.07cm 2 The conversion efficiency is 19.58% at 15.5 cm 2 The conversion efficiency of perovskite photovoltaic devices is 19.26%. As the active area increases, the conversion efficiency of perovskite photovoltaic devices decreases slightly.

[0077] The active areas of the samples prepared in the above examples and comparative examples are all 0.1 cm 2 The conversion efficiency and yield of the perovskite photovoltaic devices (the number of sample tests is 100, and the perovskite photovoltaic devices with a conversion efficiency greater than 18% are good) are shown in Table 1 below:

[0078] Table 1

[0079] Perovskite photovoltaic devices Conversion efficiency (%) Yield (%) Example 1 20.30 91 Example 2 18.01 89 Example 3 17.5 88 Example 4 25.35 53 Comparative Example 1 17.70 85 Comparative Example 2 24.69 51

[0080] It can be seen from Table 1 that, compared with Comparative Example 1, the yield of the device can be improved by introducing an inducer during the preparation of the perovskite layer, and the introduction of CuI and HI can improve the conversion efficiency of the perovskite photovoltaic device; among them, the conversion efficiency of the perovskite photovoltaic device prepared with CuI as the inducer can not only be greater than 20%, but also the yield is not less than 90%, which meets the needs of industrial production.

[0081] In addition, compared with the perovskite photovoltaic device prepared by the spin coating process to prepare the hole transport layer (Comparative Example 2), the yield of the perovskite device prepared by the full evaporation method is greatly improved. It can be seen that the full evaporation method provided by the present invention is conducive to the actual production of large-area perovskite photovoltaic devices.

[0082] 3. Attenuation factor: Draw a graph with the active area of ​​the perovskite photovoltaic device as the X-axis and the conversion efficiency as the Y-axis, and use the origin software to fit the following formula: PCE = ηA + B PCE , where PCE is the conversion efficiency, η is the attenuation factor, A is the active area, B PCE is the intercept of the tangent line of the corresponding active area at the corresponding point on the curve and the Y axis.

[0083] For the perovskite photovoltaic device prepared by the method described in Example 1, the attenuation factor η obtained by fitting by the above method is -0.06, while the perovskite photovoltaic device prepared by other methods in the prior art generally has an η of ≦-0.12. That is to say, the conversion efficiency of the perovskite photovoltaic device prepared by the full evaporation method of the present invention decreases less with the increase of the effective area. This is because the perovskite film prepared by the full evaporation method has good uniformity. It can be seen that the preparation method provided by the present invention is more suitable for the preparation of large-area perovskite photovoltaic devices.

[0084] 4. Stability test: The unpackaged perovskite photovoltaic devices prepared in Example 1 and Comparative Example 1 were subjected to operational stability tests, specifically by using an MPPT system (YH-VMPP-16) at 50±5°C and one sun irradiation (light emitting diode (LED) lamp without UV filter). The test system was placed in a glove box filled with N2, and the continuous test time exceeded 3200 hours.

[0085] The perovskite photovoltaic cell (Example 1) treated with the inducer CuI still maintained more than 80% of its initial efficiency after more than 3200 hours of maximum power point tracking (MPPT) testing. Figure 6 As shown, after the perovskite photovoltaic cell treated with the inducer CuI was continuously tested for 2697 hours, the conversion efficiency dropped to 85% of the initial efficiency, while the perovskite photovoltaic cell prepared in Comparative Example 1 was only continuously tested for 1160 hours, and the conversion efficiency dropped to 85% of the initial efficiency. It can be seen that the perovskite photovoltaic cell treated with the inducer can greatly improve the stability of the perovskite photovoltaic cell.

[0086] The above-described embodiments are only preferred embodiments for fully illustrating the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or changes made by those skilled in the art based on the present invention are within the protection scope of the present invention. The protection scope of the present invention shall be subject to the claims.

Claims

1. A method for preparing a perovskite film by evaporation, characterized in that: The following steps are involved: S1. placing a substrate in a vapor deposition chamber, and co-evaporating an inorganic salt and an inducer, wherein the inorganic salt comprises PbI2, and the inducer is selected from one or more of cuprous iodide, methyl iodide, and hydroiodic acid; S2, further evaporating an organic salt and performing an annealing treatment to form the perovskite film on the surface of the substrate; the organic salt comprises FAI.

2. The method according to claim 1, characterized in that: In S1, the evaporation rate of PbI2 is The evaporation rate of the inducer is 3. The method according to claim 1, characterized in that In S1, the inorganic salt further comprises one or more of PbCl2, CsI, CsBr, and PbBr2.

4. The method according to claim 1, characterized in that In S2, the organic salt further comprises methylamine hydrochloride; the evaporation rate of the organic salt is 5. The method according to claim 1, characterized in that In S2, the annealing treatment is performed at a temperature of 140-170°C and for a time of 10-20 minutes.

6. A perovskite film, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 5.

7. A perovskite photovoltaic cell, characterized in that: Comprising the perovskite film according to claim 6.

8. The perovskite photovoltaic cell according to claim 7, characterized in that: It includes a transparent conductive substrate layer, a hole transport layer, a perovskite layer, an electron transport layer, a hole blocking layer and an electrode layer which are stacked in sequence; wherein, The material of the hole transport layer is selected from one or more of [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, and polymer SAM; The perovskite layer is the perovskite film; The material of the electron transport layer is fullerene and / or tin oxide; The hole blocking layer is 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline and / or 2,2',2"-(1,3,5-triphenylbenzene)-tris[1-phenyl-1H-benzimidazole]; The electrode is selected from one or more of silver, gold and copper.

9. The perovskite photovoltaic cell according to claim 8, characterized in that: The thickness of the hole transport layer is 2-50nm; the thickness of the perovskite layer is 500-800nm; the thickness of the electron transport layer is 5-20nm; the thickness of the hole blocking layer is 5-15nm; and the thickness of the electrode layer is 50-200nm.

10. A method for preparing a perovskite photovoltaic cell according to any one of claims 7 to 9, characterized in that: The following steps are involved: (1) placing a transparent conductive substrate in an evaporation cavity, evaporating a hole transport layer material to form a hole transport layer; the hole transport layer material is selected from one or more of [2-(3,6-dimethyl-9H-carbazole-9-yl)ethyl]phosphonic acid, [4-(3,6-dimethyl-9H-carbazole-9-yl)butyl]phosphonic acid, and polymer SAM; (2) co-evaporating an inorganic salt and an inducer on the hole transport layer, then evaporating an organic salt, and performing annealing to form the perovskite layer on the substrate surface; the inorganic salt comprises PbI2, the inducer is selected from one or more of cuprous iodide, methyl iodide, and hydroiodic acid, and the organic salt comprises FAI; (3) Sequentially evaporating an electron transport layer material, a hole blocking layer material and an electrode material on the perovskite layer to prepare the perovskite photovoltaic cell.

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